The 12th Doctor
The 11th Doctor stumbled into the TARDIS, clutching his left heart, gasping for air. He half-fell unto the navigation console, blowing out bright yellow time vortex energy. As he spun around, in his old fashioned way, he fell. "Looks like my time is up." He said, as much to the TARDIS as to himself. His hair plastered to his forehead with sweat. He groaned with pain.
Exhaling time vortex energy, tears started to fill his eyes, he thought of the first time he met little Amelia Pond, the girl who waited. The scottish ginger from a sleepy town with a duck pond without the ducks. How she saved his life, and he hers. He thought of Rory Williams-Pond. The Last Centurion, and the boy who waited two thousand years for his love, whom he thought was more important than the whole of creation. And how he had failed them in New York.
And his mind raced to Clara. His Impossible Girl. She had saved him, time and time again, and thrice that. She was always there, but, he had not always seen her. That sassy little woman had saved him, and by extension, everyone he had ever saved. He would be forever grateful for that, but, this, he would spare her.
The Doctor was ashamed, angry and so very sad. He pulled himself up, not wanting to damage the TARDIS more than he already had before.
He ran to the door, almost falling down in the progress. The door would not open, he banged on the door, shouting: "Let me out! I've failed Rory!I failed Amy! I lost River! And now I failed myself! DON'T MAKE ME HURT YOU TOO!" The last words he screamed in desperation. The doors did not open, but the TARDIS shined with a bright orange for some seconds. Telling the Doctor: "Trust me".
That was all the Doctor needed. "Fine then." He closed his eyes. One last thought as the 11th Doctor. The Doctor straightened his bow-tie. And what are final moments without final words? "Geronimo." He almost whispered them. And finally, he let go. And colours, brighter and more beautiful than a thousand suns, broke out of his limbs and neck. The 11th hour was over.
The Doctors previous attempts to regenerate inside the TARDIS had proved to be disastrous, damaging the beautiful blue box beyond compare. But, not this time. The TARDIS flew off into the vortex of time and space. Negating the effects of the regeneration. The Doctor would still change, but, the TARDIS would be unharmed.
The Doctor screamed in both pain and joy as the change was coming to an end. And so it was. The whimsical, playful, bright and so dark Doctor was gone. In his place stood the 12th.
He staggered over to the console. Putting his hand on the dashboard. Panting and resting. Soon enough, he regained his breath, and blew out the last of the time vortex energy. He stared into the TARDIS' console. Not knowing what to do next. A whole new mindset was inside of the Doctor. Should he find every last Weeping Angel and extinguish them of the face of the universe? Learn the mandolin? Go back in time and watch Nikolas Tesla freak out over the light bulb? Watch Atlantis fall into the sea? Or maybe he should go see The Beatles preform at a small tavern in Liverpool before they got famous?
He sighed as he raised his head. "Twelve." He said slowly, with a hint of sadness, but, stern and absolute. He stood up and looked around in the TARDIS, not for anything particular. "Let's make it a good one." He said equally sad and happy, as much to the TARDIS as himself.
He started walking towards the stairs, to the dressing room, the bowtie was a little too tight for his new neck. Then he suddenly stopped. "No.." He paused and turned his neck. Half-looking at the TARDIS console. A smile emerged on his face.
"Let's make it the best one." He spun around, hitting a lever on the TARDIS, smiling. As the TARDIS started to make it's usual noise for take-off, he ran off further into the TARDIS to find a new set of clothes to match his new face. Ready for any- and everything, when- and wherever.